Overhead accumulation conveyors

ABSTRACT

This invention relates to power and free accumulation conveyors in which an element of the power conveyor when it overtakes an unrestrained halted element of the free conveyor automatically connects for movement with said free element and also releases said free element when said free element contacts a stop placed in its path or another free element which has been stopped in its path, for example, in an accumulation area. The driving dog, which is mounted on the power element, is pivotable about a vertical axis to override selective dogs on the free element through a camming mechanism.

United States Patent Leach 1 July 25, 1972 [54] OVERHEAD ACCUMULATION CQNVEYORS Primary Examiner-Arthur L. La Point Assislan! Examiner-Robert Saifer [72] Inventor: John M. Leach, PO. Box 341, Port Jefierv [22] Filed: 1971 This invention relates to power and free accumulation con- [21] A l No; 110,030 veyors in which an element of the power conveyor when it overtakes an unrestrained halted element of the free conveyor automatically connects for movement with said free element [52] lU.S.(l. and also releases Said free element when Said free element 2; f i i contacts a stop placed in its path or another free element le o are which has been stopped in its path, for example in an accumu lation area. The driving dog, which is mounted on the power [56] References Cited element, is pivotable about a vertical axis to override selective UNITED STATES PATENTS dogs on the free element through a camming mechanism. 3,523,504 8/1970 Jones 104/172 S 4 Claims, 6 Drawing Figures OVERHEAD ACCUMULATION CONVEYORS The present invention resides in the area of the interconnecting mechanism for the elements.

The movements of the elements interconnecting mechanism all occur in the horizontal plane which makes for a compact mechanism which conserves valuable head room occupied by the mechanism.

The forces exerted on the elements interconnecting mechanism both during driving of the free element as well as holdback of the free element are so directed as to increase the connecting engagement instead of decreasing it to thereby reduce the possibility of undesired release of the free element as on a descending section of the conveyor.

BACKGROUND OF THE INVENTION parts which has made them complicated in operation, expensive, and subject to rapid wear which has made them unreliable. They have also been bulky and vulnerable to damage.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an interconnecting mechanism for use between power and free elements of an accumulating conveyor which is simple in operation and economical to produce.

It is another object of the present invention to provide such a mechanism which is carried predominantly by the elements of the power conveyor because these are usually fewer in number than the free elements.

It is a further object of the present invention to provide such a mechanism which has only one moving part which is not subjected to extreme wear, is small in size, is not vulnerable to striking passing objects and is carried in a protected area.

It is another object of the present invention to provide such a mechanism in which the moving part is positively held in operative position other than just by gravity. Other objects and advantages will be apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings FIG. 1 is a side elevational view of an interconnecting mechanism for power and free conveyor elements constructed in accordance with the present invention:

FIGS. 2, 3, 4 and 5 are sectional views taken on the plane indicated by line A A of FIG. I and looking in the direction of the arrows and showing various operating positions of the mechanism, and

FIG. 6 is an enlarged fragmentary view of the pivotal connection between the single moving part and the free element and the mounting for the biasing spring for the moving part.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION The interconnecting mechanism of the present invention can be used on just about any one of the known types of power and free conveyors. That is the power and free units may be of the type shown by U.S. Pat. No. 3,377,962 in which the power conveyor is an l-Beam track monorail and the free conveyor elements which support the load are of the mulit-truck type, or as shown by US. Pat. No. 3,418,948 in which the track is an enclosed box section type and the free conveyor elements which support the load are of the single truck type. The mechanism can be connected to any desired movable element of the power element such as the chain as shown in the first patent; to a trolley as shown in the second patent; to a load bar extending between two trolleys or to any other desired moving element.

The fragmentary element 10 shown in FIG. 1 represents such desired moving element of a power conveyor, and the concomitant, sub-positioned fragmentary element 12 represents such a load carrying element of a free conveyor which is driven by the power conveyor element through the mechanism of the present invention.

A bolster 14 has projections 16 which are suitably attached to the element 10 as by welding or can be formed integrally with the element 10.

The only movable member 18 of the mechanism is elongated and provided near one end with a driving dog 28 and near the opposite end with a holdback dog 30. The member 18 is provided with a pivot pin 20 which extends up through a bearing hole 22 in the bolster l4 and carries a collar 24 on its top held to the pin by a taper pin 26 or any other well known type of fastening. A torsion spring 32 surrounds the pin 20 and is anchored in a socket 34 in the bolster l4 and a socket 36 in the member 18. The spring 32 biases the member 18 to rotate in a counterclockwise direction as shown in FIG. 4. A stop pin 38 suitably fastened to the bolster 14 holds the member 18 stopped in the position shown in FIGS. 1 and 4 in which its major axis extends in the direction of travel of the conveyor elements as shown by the arrow in FIG. 1.

Each free element 12 is provided with a driving stud 40 near its forward end and a deflector stud 42 at its rear end. The dimension of the stud 40 in its direction of travel is less than the distance between the inner faces of the driving dog 28 and the holdback dog 30, and the same dimension of the deflector stud is greater than the distance between the dog faces.

The forward end of the member 18 is shaped to provide a cam area 48.

When the member 18 approaches a halted free element 12 the cam area 48 first contacts the rounded face 44 of the deflector stud 42 which deflects the member 18 so as to rotate it clockwise against the force of the spring 32. As the member 18 continues to move it also rotates until the edge 50 on the holdback dog 30 contacts the side face 52 of the stud 42 and slides along this face until it rides off of the leading end of the stud 42 as shown in FIG. 2. At the same time the driving dog 28 has swung around the opposite side of the stud 42 as also shown in FIG. 2. When the edge 50 of the holdback dog 30 rides off of the end of stud 42 the driving dog swings back and contacts the nearest face of the stud 42 until it also rides off of the end of stud 42 when it assumes the position shown in FIG. I.

As the member 18 continues on, the cam area 48 will contact the rounded end 46 of the driving stud 40 and again be deflected until the edge 50 contacts and rides along the nearest side face of the stud 40 until it rides off of the stud which will cause the member 18 to immediately straighten out under the force of the spring 32 and as the member 18 moves on the driving dog 28 will be brought up against the driving stud 40 as shown in FIG. 4 which will move the free element 12 along with the power element 10.

When a free element 12 is not free to move as in the above situation as when it is the rear end one of a group in an accumulation area its driving stud 40 will be in contact with the deflector stud 42 of the next free element as shown in FIG. 5. When an approaching member 18 contacts and is deflected clockwise as explained above by the driving stud 40 its edge 50 can not ride off of the driving stud because the stud 42 of the next free element is in contact with the driving stud and the edge 50 continues on along the side face 52, as shown in FIG. 5, so that the driving dog 28 can not swing behind and contact the stud 40 as above but continues on and rides off of the leading edge of the stud 42 so that the rearmost free element I2 is thus bypassed and not picked up.

When the member 18 continues on in the situation just explained, it will contact the driving stud 40 of the next free element and again be deflected as above. If the next free element is not restrained by another element it will then be picked up and moved away as shown in FIG. 4. If the said next free element is restrained by another free element its driving dog 40 will also be by-passed as shown in FIG. 5 and the member 18 will automatically continue along the group of accumulated free elements until it finds one which is not restrained which it will pick up and move away as shown in FIG. 4. This will continue as following members 18 approach until all in the group are moved away unless other free elements are constantly being added to the group. This occurs whenever a free element being moved along by a power element approaches a halted free element. The member 18 will contact the stud 42 of the halted free element and be deflected as shown in FIG. 2 which will cause the driving dog 28 to move out from behind the driving dog 40 and thus release the moving free element and leave it with its driving dog 40 in contact with the deflector dog 42 of the next free element as shown in FIG. 5.

When it is desired to stop any moving free element for any reason such as starting an accumulation area it is only necessary to move a stop member carried by any suitable slide and shaped just like a deflector stud 42 into the path of an approaching member 18 moving the free element to be stopped so that the stop member shaped like stud 42 can deflect the member 18 and release the driving dog which it is driving in the same manner as described above and as shown in FIG. 5. The stopped free element will remain in stopped condition until the stop member is removed from in front of it.

The distance between the cam 48 on the member 18 and the pivot pin 20 is made much greater than the distance between the face 29 on the driving dog 28 and the pivot pin 20 in order to create a mechanical advantage which is advantageous in moving the face 29'out from behind the face 46 on the driving stud 40 when there is a load on the free load carrying element 12.

It will be noted that the driving dog 28 and the holdback dog 30 pass on opposite sides of the driving stud and deflector stud 42 while moving by these studs. This prevents the member 18 from projecting very far to either side of the elements l2 and thus provides a compact construction which is not vulnerable to hanging up on objects being passed by a moving element 12.

The power conveyor shown and described in U.S. Pat. application Ser. No. 831,382, filed June 9, I969, now U.S. Pat. No. 3,589,503 makes an excellent power conveyor for use with the present invention.

It is to be understood that the foregoing is to be considered as descriptive and not limitative because many changes and modifications can be made in the physical structure of the present invention without departing from its'scope.

The invention having been described, what is claimed is:

1. In a power and free accumulation conveyor system involving power driven conveyor elements and concomitant sub-positioned free load carrying conveyor elements, the improvement consisting of mechanism for releasably interconnecting selected power and free elements for movement together comprising an elongated member having a driving dog near one end thereof and a holdback dog near the other end thereof and a cam area on the end thereof near the holdback dog, a vertical axis pivotal connection between a power driven element and said member and intersecting said member between said driving dog and holdback dog, biasing means urging rotation of said member in one direction about said pivotal connection, stop means for said member to hold it against such rotation and in a position with its longitudinal axis in the direction of movement of said elements with the cam area forwardly, a driving stud located forwardly and a deflector stud located rearwardly on each of said free conveyor elements,v said driving stud being smaller and the deflector stud being larger measured in the direction of movement of said elements than the distance between said driving and holdback dogs, and said studs being in positions to be contacted one after the other by said cam area of said member as it moves along to thereby rotate said member about said pivotal connection against the action of said biasing means when said member approaches a halted free element.

2. A conveyor system as described in claim 1, further characterized in that when said member is rotated about said pivotal connection the holdback and driving dogs lie on up posite sides of said studs.

3. A conveyor system as described in claim 1, further characterized in that the distance between the said cam surface and said pivotal connection is greater than the distance between said driving dog and said pivotal connection to thereby create a mechanical advantage which is advantageous in moving the driving dog away from the driving stud when the said cam area contacts a deflector stud.

4. A conveyor system as described in claim 1, further characterized in that said biasing means is a spring. 

1. In a power and free accumulation conveyor system involving power driven conveyor elements and concomitant sub-positioned free load carrying conveyor elements, the improvement consisting of mechanism for releasably interconnecting selected power and free elements for movement together comprising an elongated member having a driving dog near one end thereof and a holdback dog near the other end thereof and a cam area on the end thereof near the holdback dog, a vertical axis pivotal connection between a power driven element and said member and intersecting said member between said driving dog and holdback dog, biasing means urging rotation of said member in one direction about said pivotal connection, stop means for said member to hold it against such rotation and in a position with its longitudinal axis in the direction of movement of said elements with the cam area forwardly, a driving stud located forwardly and a deflector stud located rearwardly on each of said free conveyor elements, said driving stud being smaller and the deflector stud being larger measured in the direction of movement of said elements than the distance between said driving and holdback dogs, and said studs being in positions to be contacted one after the other by said cam area of said member as it moves along to thereby rotate said member about said pivotal connection against the action of said biasing means when said member approaches a halted free element.
 2. A conveyor system as described in claim 1, further characterized in that when said member is rotated about said pivotal connection the holdback and driving dogs lie on opposite sides of said studs.
 3. A conveyor system as described in claim 1, further characterized in that the distance between the said cam surface and said pivotal connection is greater than the distance between said driving dog and said pivotal connection to thereby create a mechanical advantage which is advantageous in moving the driving dog away from the driving stud when the said cam area contacts a deflector stud.
 4. A conveyor system as described in claim 1, further characterized in that said biasing means is a spring. 